The U.S. Senate was deadlocked on Friday over whether to extend authorization for the National Security Agency's massive collection of domestic telephone records, with Majority Leader Mitch McConnell insisting the surveillance program should continue with no new limits.

With a weekend deadline looming, McConnell advocated for extending the section of the Patriot Act that the NSA has used to justify its collection of millions of U.S. phone records over the last nine years. Section 215 of the Act, which allows the agency to collect any telephone and business records relevant to a counterterrorism investigation, expires June 1, and Congress is scheduled to take a week-long recess starting this weekend.

The Senate may work into the weekend to pass an extension to Section 215. If it fails to act in time, the NSA phone records program would be shut down before midnight on Sunday, May 31, according to the Department of Justice. Congress could still renew the program after it returns from its Memorial Day recess in early June.

McConnell, a Kentucky Republican, pushed for a two-month extension of Section 215 with no new limits on bulk telephone records collection. Several other senators called on him to allow a vote on the USA Freedom Act, an alternative bill that aims to end that practice by the NSA, while allowing it to continue collecting some records in a more targeted manner.

McConnell's resistance to the USA Freedom Act is a "dangerous game," Berin Szoka, president of conservative think tank TechFreedom, said by email. "If Section 215 sunsets, creating a gap in U.S. intelligence capabilities, then the majority leader will have no one to blame but himself. Section 215 may have legitimate targeted uses, but neither the House nor the American people will accept its renewal without ending bulk collection."

But supporters of the USA Freedom Act can give no guarantees that it will protect the U.S. from terrorism as effectively as the current NSA records collection program does, McConnell said Friday.

The USA Freedom Act would leave telephone records in the hands of carriers, instead of the NSA, and the bill doesn't require the carriers to retain the records, McConnell noted. In some domestic counterterrorism cases, "time is of the essence," he said. "The untried, and as of yet, nonexistent bulk collection program envisioned under that bill would be slower and more cumbersome than the one that currently helps keep us safe. At worse, it might not work at all."

Officials with President Barack Obama's administration, which supports the USA Freedom Act, haven't been able to guarantee its data collection program will work, McConnell said. Administration officials have said "they would let us know about any problems after the current program was replaced with a nonexistent system," he said. "This is beyond troubling."

Other senators have questioned whether the current bulk collection program helps catch terrorists. The DOJ's inspector general, in a report released Thursday, said the FBI could not point to the telephone records collection leading to "any major case developments" in counterterrorism investigations.

While McConnell has pushed for a straight reauthorization of Section 215, Senator Rand Paul, a fellow Kentucky Republican, said Thursday he will push for several amendments to any bill to extend the program, including several proposals to further limit NSA surveillance, that were defeated in the House's debate over the USA Freedom Act. Paul engaged in a 10-and-a-half-hour filibuster Wednesday to stall a vote on extending Section 215.

Any late amendments to the USA Freedom Act could effectively cause Section 215 to expire, with the House leaving on its Memorial Day break soon. Senate amendments would have to be approved by the House before a bill is sent to Obama for his signature.

Other senators called on McConnell to allow a vote on the USA Freedom Act. The bill had broad bipartisan support in the House, said Senator Harry Reid, a Nevada Democrat. Early this month, the U.S. Court of Appeals for the Second Circuit ruled that Section 215 of the Patriot Act didn't authorize the bulk collection of domestic phone records, Reid noted.

"How can we extend an illegal act?" Reid said.

The House sponsors of the USA Freedom Act also urged a Senate vote. Any other action by the Senate would effectively shut down the NSA's records collection program, they said, because the House wouldn't have time to act on any other bills passed by the Senate before the Memorial Day recess.

Failure to pass the USA Freedom Act would mean that Section 215 of the Patriot Act will expire, four sponsors of the bill, including Republican Representatives Bob Goodlatte of Virginia and Jim Sensenbrenner of Wisconsin, said in a joint statement.

"While Section 215 was used to wrongly justify the governments bulk collection program, it is also routinely used by the FBI in individual national security investigations to identify and apprehend terrorists and spies," they said. "The USA Freedom Act eliminates bulk collection while retaining the necessary tools to maintain our national security."

Meanwhile, protestors in more than a dozen U.S. cities rallied Thursday evening and called on Congress to allow Section 215 of the Patriot Act to expire.

Grant Gross covers technology and telecom policy in the U.S. government for The IDG News Service. Follow Grant on Twitter at GrantGross. Grant's email address is grant_gross@idg.com.

Copyright 2018 IDG Communications. ABN 14 001 592 650. All rights reserved. Reproduction in whole or in part in any form or medium without express written permission of IDG Communications is prohibited.